Mechanism for increasing jettison clearance

ABSTRACT

Embodiments of the present invention generally relate to a novel system, device, and methods for providing a one-way locking mechanism that changes the shape or stiffness of a structure. More specifically, embodiments of the present invention relate to a mechanism for increasing fairing jettison clearance. Embodiments of the present invention permit outward breathing displacement by the fairing, but reduce the inward breathing displacement by the fairing such that the fairing does not hit and damage the spacecraft or vehicle as it is jettisoned from the spacecraft or vehicle.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims priority toU.S. patent application Ser. No. 15/624,573 filed Jun. 15, 2017, titled“Mechanism for Increasing Jettison Clearance,” which is incorporated byreference in its entirety herein.

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to a one-waylocking mechanism that changes the shape or stiffness of a structure,and more specifically to a mechanism for increasing fairing jettisonclearance.

BACKGROUND OF THE INVENTION

A launch vehicle is used to launch a payload into orbit around the earthor toward a path outside of earth's orbit. A fairing (also referred toas a payload fairing or a launch vehicle adapter (“LVA”) fairing) istypically used to protect the payload or other portions of the upperstage before and during launch. A payload fairing surrounds the payloadin the nose portion of the launch vehicle and a LVA fairing typicallysurrounds a portion of the spacecraft aft of the LVA or upper stage. Theterm “fairing” is used herein to reference all types of fairings. Thefairing is detachably mounted to the upper stage of the launch vehicle.Once the rocket leaves earth's atmosphere, the fairing is separated fromthe launch vehicle and discarded to eliminate weight and prepare forseparation of the payload. See FIG. 1 showing a launch vehicle 4 (alsocalled a vehicle herein) with two fairings 8A, 8B separated from thespacecraft 12 (also called a payload herein). Each fairing 8A, 8B has aheight H, a bottom edge 16 opposite a tip 20, a first axial edge 24separated from a second axial edge 28 by the bottom edge 16. Thefairings 8A, 8B have a half cylinder or an arcuate shape with a partialcircumference (i.e., arc length), radius, radius of curvature, aninterior surface (also called an inboard surface herein) 32, and anexterior surface (also called an outboard surface herein) 36. Thecross-hatching (shading) on the fairings 8A, 8B show the areas of thefairings 8A, 8B that experience the most inward and outward deflectionduring jettison.

Typically, explosives (e.g., high-energy linear explosive rails),balloons, ballasts, or other force imparting systems are used toseparate the two or more payload fairings from each other and from thelaunch vehicle and to push the payload fairings away from the launchvehicle or spacecraft. FIG. 2A shows a cross-section of the launchvehicle 4 with two fairings 8A, 8B before the fairings 8A, 8B haveseparated from the spacecraft 12, i.e., at time t0. The fairings 8A, 8Bhave a width W extending from one edge 24 to the other edge 28. Theinner radius R1, R1′ of the fairings at time t0 is shown and is alsocalled the fairing's static inner radius R1, R1′. Dimension R1corresponds to the edges 24, 28 of the fairing 8A, 8B and dimension R1′corresponds to the centerline or apex 50 (also called the backboneregion) of the fairing 8A, 8B. R1=R1′ at time t0. As the fairings 8A, 8Bare jettisoned away from the spacecraft 12, the fairings 8A, 8B firstflex or “breathe” outward and away from the spacecraft 12 due to theforces imparted on the fairings 8A, 8B to push the fairings 8A, 8B awayfrom the vehicle 4. This is shown in FIG. 2B by the fairings 8A₁, 8B₁ insolid lines. FIG. 2B is also a cross-sectional view of the launchvehicle 4 shown in FIG. 2A, but at a later time t1. The solid linefairings 8A₁, 8B₁ at time t1, just after the fairings 8A₁, 8B₁ have beenjettisoned away from the spacecraft 12, flex or breathe outward as aresult of the separation. As each fairing 8A₁, 8B₁ breathes outward, itsinner radius R2 at the edges 24, 28 and its distance from the spacecraftincrease compared to that shown in FIG. 2A. Thus, R2 is greater than R1(R2>R1). Conversely, dimension R2′ corresponding to the fairingcenterline or apex 50 decreases compared to dimension R1′. Thus,R2′<R1′. Next, at time t2, the fairing 8A₂, 8B₂ seeks to return to thenatural shape following dissipation of the separation energy. Eachfairing 8A₂, 8B₂, flexes or breathes inward toward the spacecraft 12 asshown by the fairings 8A₂, 8B₂ in dashed lines in FIG. 2B. The inwardbreathing of the fairing 8A₂, 8B₂ reduces the fairing's inner radius R3to less than the fairing's original static inner radius R1 and increasesthe dimension R3′ compared to dimension R1′. If the fairings 8A₂, 8B₂are not far enough away from the spacecraft 12 at time t2, then therecoiling edges 24, 28 of the fairings 8A₂, 8B₂ will hit and can damagethe spacecraft 12 or vehicle 4.

Prior solutions to the problem of the fairings flexing or breathinginward and hitting the spacecraft or vehicle include ensuring that theradial jettison velocity is large enough that the fairing has separatedfar enough away to gain clearance to accommodate the recoil or inwardbreathing of the fairing at the fairing split-line. However, maintainingclearance to the non-jettisoning hardware is challenging. One solutionis to increase the energy of the separation explosion to ensure thefairing is sufficiently separated from the spacecraft such that therecoil of the fairing is irrelevant. However, high-energy linearexplosive rails create significant vibrations and shocks that can damagecomponents and instrumentation. Similarly, connections based onpyrotechnic strings or explosive bolts are effective and reliable butthey generate high levels of vibratory disturbance or shocks which movealong the whole vehicle and spacecraft until reaching the most sensitiveelements. Mission success of spacecraft, aircraft, and rockets isdependent upon components and instrumentation continuing to operatethroughout an entire flight and beyond deployment, for example, in thecase of a satellite. Previous attempts also include ballasts added tothe split-line in order to achieve the clearance needed. However, theseballasts add significant weight—which is not desired for spacecraft orvehicles. It takes a significant split-line ballast to achieve even asmall increase in breathing clearance. In other prior art solutions,supplemental springs are used to increase the clearance distance bymodifying the trajectory of the fairing, but the energy per mass andvolume in springs is low, and therefore not ideal for applications whereweight or space is limited. Additionally, springs can be used tosupplement the jettison of a fairing whose primary separating force is abellows, or the like, or linear explosive assembly. Alternatively,springs can be used as the primary separating force themselves, whichwill impart less energy into the fairing separation and which generallydoes not excite the breathing modes as significantly due to springs'lower energy content. However, separation velocity is generally alsodecreased with springs.

Another existing solution is to decrease the breathing frequency of thefairing by decreasing the stiffness of the fairing in the breathingdirection. However, this solution has drawbacks, including a softer, andoften heavier, fairing that typically conflicts with other requirementsfor buckling strength and vibro-acoustics.

Accordingly, there exists a significant and long-felt need for amechanism that increases fairing jettison clearance without addingsignificant extra weight and without creating additional vibrations andshocks.

SUMMARY OF THE INVENTION

Aspects of the present disclosure relate to novel systems, devices, andmethods for providing a mechanism that uses deflection to lock astructure in a more open position, and more specifically to a one-waylocking mechanism for increasing jettison clearance. The mechanismallows the shape or stiffness of a structure to change during jettisonand then holds the new shape. The novel mechanisms are lighter, lessexpensive, and outperform prior art mechanisms used to increase jettisonclearance. Additionally, the novel mechanisms allow for larger payloadsto fit within the same fairing envelope than previous designs becauseprevious designs needed more clearance between the payload/spacecraftand the vehicle.

It is one aspect of embodiments of the present invention to provide amechanism that permits outward flexing or breathing displacement by thefairing and also reduces the inward breathing displacement by thefairing such that the fairing does not hit and damage the spacecraft orvehicle after being jettisoned from the spacecraft or vehicle.Embodiments of the present invention permit the fairing to flex orbreathe outwardly by only minimally contributing to the outwardbreathing stiffness and deflection of the fairing. In some embodimentsof the present invention, the recoil or inward breathing displacement ofthe fairing is reduced by locking the fairing in a more open position(i.e., a position with the larger inner radius at the fairing edges). Insome embodiments, the present invention uses a one-way locking mechanismto lock the fairing in an open position.

Embodiments of the present invention provide a mechanical means to alterthe stiffness (e.g., the breathing stiffness), the displacement (e.g.,the breathing displacement), and the static form of the jettisonedstructure. Embodiments of the present invention use a mechanical meansto alter the breathing stiffness by preventing or limiting the amountthe fairing can flex or breathe inward after being jettisoned from thespacecraft. Further, embodiments of the present invention use amechanical means to alter the breathing displacement of the fairing bylimiting the amount the fairing can displace inwardly after jettison.Finally, some embodiments of the present invention use a component orsubassembly to alter the post-jettison static form of the jettisonedstructure after the fairing is jettisoned from the spacecraft by lockingthe fairing in an open position and changing its post jettison staticform.

Another aspect of embodiments of the present invention is to provide amechanism to increase jettison clearance that also allows the fairing tobe stiffer. A stiffer payload fairing is desirable for a number ofreasons, including that it increases the overall strength of the fairingand reduces the low frequency vibration responses in flight.Additionally, vehicle hardware is more efficient when it is stiffer andlighter, but that is in direct conflict with jettison clearance because,traditionally, to obtain positive jettison clearances a soft and heavyfairing was desired. Therefore, the present invention can be associatedwith a fairing that is stiffer than traditional fairings and themechanism will still increase the jettison clearance between the fairingand the spacecraft or vehicle. Accordingly, embodiments of the presentinvention remove conflicts in requirements between jettison clearance,shock environments, vibro-acoustics, and strength.

Another aspect of embodiments of the present invention is to provide amechanism to increase jettison clearance that also increases thepayload/spacecraft volume and provides a more efficient overall design.Payload volume is increased through embodiments of the present inventionbecause less static clearance between the payload and fairings isneeded, meaning there is less space between the payload and thefairings. Thus, the fairings have a smaller diameter than in previousdesigns and/or the payload can be larger than in previous designs.Smaller fairings are typically lighter weight and less expensive.Additionally, the fairing can be lighter and stiffer than in previousdesigns because the present invention increases jettison clearance.

It is another aspect of embodiments of the present invention to providea one-way locking mechanism that changes the shape or stiffness of astructure (e.g., piece of equipment or vehicle component) usingdeflection. Embodiments of the mechanism prevent, or at least limit, theamount of displacement in one direction—for example, the inwarddirection. The mechanism allows expansion in the opposite direction—forexample, the outward direction. In some embodiments, the presentinvention is a mechanical means applied to the payload fairing to alterthe breathing stiffness, displacements, and static form of the fairingafter it has been jettisoned away from the spacecraft.

It is one aspect of embodiments of the present invention to provide aone-way locking mechanism to increase jettison clearance that ispositioned in an accessible location for installation, modifications,and repair. Additionally, the location of the mechanism limits damage tothe mechanism during launch and spaceflight. Therefore, in someembodiments described herein, the novel one-way locking mechanism isplaced on the inboard face of the fairing. In an alternative embodiment,a portion of the novel one-way locking mechanism is placed on theoutboard face of the fairing while the remaining portions of themechanism are on the inboard face of the fairing. The mechanism can bepositioned on the central section of the jettisoned structure in thearea where the structure experiences the greatest amount of strain,e.g., the backbone region of a fairing, which is proximate the apex orcenterline of the fairing. It should be further appreciated thatmultiple mechanisms may be employed, rather than a single mechanism.

The mechanism is also positioned in a location where it will notinterfere with other components, such as the explosive rails or ballastsalong the split line, and still have a significant impact on the inwardbreathing displacement. In various embodiments, the novel one-waylocking mechanism is positioned proximate the apex of the fairing at oneor more locations along the height or longitudinal axis of the fairing.

It is one aspect of embodiments of the present invention to provide amechanical means to alter the breathing stiffness and the inwardbreathing displacement of a jettisoned structure that is easy andinexpensive to manufacture. In some embodiments, the mechanism has gaps,slots, or holes that open during jettison and then are plugged by pins,wedges, shims, or other devices to prevent inward deflection. Themechanism uses simple and easy to manufacture shapes and parts.

In one embodiment, the novel mechanism includes a band portion with anaperture and a slit extending from the aperture to one edge of the bandportion, and a spring-loaded pin with a spring, nut, and a pin with ahead, cylindrical portion, and thick cylindrical portion positionedbetween the head and the cylindrical portion. The initial aperture isthe size of the cylindrical portion of the pin (or slightly larger) andis smaller than the size of the thick cylindrical portion of the pin. Asthe fairing breathes outward, the aperture and slit open allowing thethick cylindrical portion of the pin to fall down (or be pushed by thespring) into the now-larger aperture. The thick cylindrical portionprevents the aperture and slit from closing and returning to theiroriginal shapes, thus changing the fairing's static form to be in a moreopen position and also increasing the inward breathing stiffness of thefairing to limit the amount the fairing can breathe inward. In furtherembodiments, multiple band portions or mechanisms are positionedside-by-side along the inboard face of the fairing.

Another embodiment is a simplified version of the mechanism describedabove because it does not use the spring-loaded pins. This embodimentincludes a band (also called an elongate member herein) positioned alongthe inboard face of the fairing. The band may be comprised of multiplesmaller bands side-by-side or may be one big band with slits extendingfrom the inboard surface of the band to the band's surface proximate theinboard surface of the fairing proximate the backbone region. The slitsallow the band to expand or breathe outward because it can separatealong the slits, but the band limits the amount the fairing can breatheinward because it increases the fairing's inward breathing stiffness.However, this embodiment cannot alter the static form of the fairing,meaning it cannot lock the fairing in a more open position than theoriginal static position. Rather, the band increases the inwardbreathing stiffness of the fairing to reduce the maximum inwardbreathing displacement of the jettisoned fairing and, thus, reduces therisk of spacecraft damage during fairing separation.

Another embodiment of the novel mechanism includes two racks of teethpositioned on the inboard surface of the fairing at the apex of thefairing. In this embodiment, as the fairing breathes outward duringjettison, the teeth slide past each other. Then, when the fairing startsto breathe inward, the teeth catch one another and lock to lock thefairing in a more open position and limit the fairing's inwarddisplacement during inward breathing. Thus, this embodiment changes boththe static form of the jettisoned fairing and the inward breathingstiffness of the fairing. This embodiment permits outward breathing ofthe fairing because it does not increase the outward breathing stiffnessof the fairing.

Yet another embodiment of the present invention uses a spring-tensionedwebbing strap on the outboard face of the structure (e.g., fairing) andeach end of the strap is in tension with a torsion spring housed in aninertia reel. As the fairing initially breathes outward after jettison,the strap is retracted into the inertial reels. Then as the fairingbreathes inward, the inertial reels lock and prevent the strap fromunwinding out of the reels to change both the static form of thejettisoned fairing and the inward breathing stiffness of the fairing.This embodiment permits outward breathing of the fairing because it doesnot increase the outward breathing stiffness of the fairing.

An additional embodiment includes a damper with a piston, where a rodinterconnected to the piston on one end is interconnected to theinterior surface of the fairing on the other end. Generally, extensionof the damper would occur during the initial outward breathing of thefairing, as excited by the initial separation force impulse. A very lowdamping force would be applied during the extension stroke (while thefairing is breathing outward) allowing the fairing to open as far as itcan during the initial breathing. As the fairing transitions from theinitial outward breathing, the damper also transitions to a compressionstroke. The damping on the compression stroke would provide a very highforce to slow the rate of inward breathing significantly. Therefore, thedamper is set for very overdamped during the compression stroke when thefairing begins to breathe inward. Accordingly, compression would becontraction of the damper from the extended state post-jettison afterthe fairing begins to breathe inward back toward the payload or vehicle.

The damper has a housing with a valve on one end and the rodinterconnected to the piston exits the housing on the other end. Thehousing may be a cylindrical housing or have any other shape known inthe art. The valve may be a one-way valve, or other type of valve usedin dampers or shock absorbers. In its static state before fairingseparation, the piston is mostly in the housing of the damper and ispositioned proximate the end of the housing with the valve. As thefairing breathes outward, the piston is pulled away from the valve andtoward the other end of the housing. The housing also fills with fluidthat enters through the valve as the piston is pulled away from thevalve and toward the other end of the housing. The fluid could behydraulic fluid, air, or another fluid. When the fairing begins tobreathe inward, the damper restricts motion of the piston in an inwarddirection, which restrains the fairing motion, because the fluid now inthe damper cannot exit through the valve or can only exit the valve veryslowly. Thus, the fairing is restrained in a more open position by thedamper. In further embodiments, more than one damper can be used. Thedampers may be linearly aligned horizontally or vertically, or in anyother orientation, or as an array. The dampers may also cross over oneanother depending on the number of dampers desired.

The damper may be similar to a shock absorber or hydraulic shockabsorber. Accordingly, U.S. Pat. No. 5,586,627 to Nezu et al. entitled“Hydraulic Shock Absorber of Damping Force Adjustable Type” and U.S.Pat. No. 4,917,222 to Bacardit entitled “Shock Absorber” areincorporated by reference herein in their entireties.

In one embodiment, a mechanism for increasing jettison clearance isprovided comprising: a band for interconnection to an inner surface of ajettisoned structure, the band comprising: an upper surface; a lowersurface opposite the upper surface; an inner surface; an outer surfaceopposite the inboard surface and proximate the inner surface of thejettisoned structure; a plurality of apertures; and a plurality ofslits, wherein each slit extends from each aperture to the inner surfaceof the band; a plurality of blocking members, wherein each blockingmember comprises: a biasing member; a locking mechanism; and a pinhaving a head on a first end, the head interconnected to an enlargedportion that is interconnected to a cylindrical portion extending to asecond end; wherein each blocking member is positioned in each aperture.

In additional embodiments, the head of the pin is positioned above theband and the biasing member is positioned below the band and when themechanism is in a first position the cylindrical portion of the pin ispositioned in the aperture, and when the mechanism is in a secondposition the enlarged portion of the pin is positioned in the aperture.In further embodiments, the biasing member is a spring and the lockingmechanism is a nut with a threaded through hole, and wherein the lowerportion of the cylindrical portion is threaded to threadingly engage thenut; the mechanism is positioned on an interior surface of a fairing;and/or the mechanism is positioned on a backbone region of the fairing.In some embodiments, the enlarged portion of the pin comprises a taperedsurface proximate the cylindrical portion to facilitate movement intothe aperture and the band increases an inward breathing stiffness of thefairing.

In one embodiment, an apparatus for altering the shape of a fairingfollowing separation from a spacecraft is provided comprising: a fairinghaving a curved shape with an interior surface, an exterior surface, afirst edge, a second edge, and a width defined as the dimension betweenthe first edge and the second edge; a band disposed along at least aportion of the width of the interior surface of the fairing, the bandhaving a plurality of adjacent band portions; at least one band portionhaving an aperture extending through the band portion, and a slotextending through the band portion and extending from the aperture to afirst edge of the band portion; a blocking member positioned adjacentthe aperture, the blocking member having a size larger than theaperture; a biasing mechanism associated with the blocking member andconfigured to force the blocking member into the aperture, wherein whenthe fairing is flexed outward, the slot in the at least one band portionseparates and the aperture in the at least one band portion enlarges andthe biasing mechanism forces the blocking member into the aperture.

In further embodiments, the blocking member comprises a pin having afirst end and a second end, a head portion positioned proximate firstend, an enlarged body portion positioned adjacent the head, and a secondbody portion positioned at the second end, and wherein when the fairingis connected to the spacecraft, the enlarged body portion is orientedadjacent to the aperture, and when the fairing is flexed outward, theenlarged body portion is forced into the aperture by the biasingmechanism and the biasing mechanism comprises a spring configured toforce the enlarged body portion of the pin into the aperture when thesize of the aperture is enlarged. In some embodiments, the enlarged bodyportion of the pin comprises a tapered surface to facilitate movementinto the aperture and further comprising a platform affixed to the pinproximate the second end, and the wherein the spring is positionedbetween the platform and the band portion and the second body portion ofthe pin is threaded and the platform is a nut threaded to the secondbody portion of the pin. In various embodiments, the band furthercomprises a plurality of apertures, each aperture having an associatedslot extending through the band from the aperture to the first edge ofthe band and/or the apparatus further comprises a plurality of adjacentbands, wherein at least some of the bands include apertures, slots,blocking members, and biasing members. In further embodiments, theapparatus comprises a plurality of adjacent bands, wherein each band inthe plurality of bands comprises an aperture, a slot, a blocking member,and a biasing member.

In one embodiment, a method of constructing a fairing for use with aspacecraft is provided comprising: providing a panel structure, thepanel structure having an interior surface, an exterior surface, abottom edge, and a first side edge and a second side edge separated bythe bottom edge; mounting an elongated band to the interior surface ofthe panel structure, the elongated band comprising at least one apertureextending through the elongated band and at least one slot extendingthrough the elongated band from the aperture to an interior surface ofthe elongated band; mounting a blocking member in association with theat least one aperture, the blocking member configured to move between afirst position adjacent the at least one aperture and a second positioninside the at least one aperture; mounting a biasing member inassociation with the blocking member, the biasing member configured tomove the blocking member from the first position to the second positionupon enlargement of the at least one aperture.

In further embodiments, the step of mounting the elongated bandcomprises mounting a plurality of adjacent band portions to form theelongated band, wherein some of the band portions comprise an apertureextending through the band portion and a slot extending from theaperture to an interior surface of the band portion. Moreover, mountinga blocking member comprises mounting a pin having a first end opposite asecond end, a head portion positioned proximate first end, an enlargedbody portion positioned adjacent the head, and a second body portionpositioned at the second end, wherein the enlarged body portion isseated at one end of the aperture and is sized larger than the apertureand mounting the biasing member comprises mounting a spring on anopposite side of the band from the enlarged body portion of the pinand/or the biasing member comprising a spring, and the method furtherincludes mounting the spring on the same side of the band as theenlarged body portion.

In one embodiment, a fairing is provided comprising: an interiorsurface; an exterior surface; a first axial edge; a second axial edge;an arcuate shape with a radius; an apex between the first axial edge andthe second axial edge; and an apparatus for controlling a shape of thefairing following separation from a spacecraft, the apparatuscomprising: an elongate member made of substantially incompressiblematerial, wherein the elongate member is positioned along at least aportion of the interior surface of the fairing and proximate the apex ofthe fairing, the elongate member comprising: a first side positionedopposite the interior surface of the fairing; an upper surface extendingfrom the first side to the interior surface of the fairing; a lowersurface opposite the upper surface and extending from the first side tothe interior surface of the fairing; a plurality of slits extending fromthe portion of the elongate member proximate the interior surface of thefairing to the first side and extending from the upper surface to thelower surface, wherein the plurality of slits allows the elongate memberto separate along the plurality of slits which allows the fairing tobreathe outward following fairing separation, and wherein when thefairing recoils inward during inward breathing the elongate memberlimits an inward breathing displacement of the fairing by increasing aninward breathing stiffness of the fairing.

In further embodiments, the apparatus for controlling the shape of thefairing limits the amount a radius of curvature of the fairing candecrease following separation from the spacecraft and the fairing has afirst radius of curvature proximate the apex prior to separation fromthe spacecraft, a second radius of curvature proximate the apexfollowing separation and while the fairing is breathing outward, and athird radius of curvature as the fairing breathes inward, wherein theapparatus prevents the third radius of curvature from beingsignificantly smaller than the first radius of curvature. In someembodiments, the first axial edge is positioned a distance from thespacecraft after the fairing separates from the spacecraft, and whereinthe apparatus limits the amount the distance can decrease as the fairingbreathes inward.

In one embodiment, a fairing is provided comprising: a curved shape withan interior surface; first axial edge; a second axial edge; an arcuateshape with an arc length and a radius; an apex between the first axialedge and the second axial edge; a height; and a means for altering theshape of the fairing following separation from a spacecraft, wherein themeans for altering the shape of the fairing limits a distance thefairing can breathe inward following outward breathing after separatingfrom the spacecraft. In additional embodiments, the means for alteringthe shape of the fairing comprises: an elongate member configured to bedisposed along at least a portion of the arc length of the interiorsurface of the fairing and proximate the apex of the fairing, whereinthe elongate member comprises: a plurality of adjacent band portions,wherein each band portion in the plurality of adjacent band portions hasa rear side positioned adjacent the interior surface of the fairing, aninterior side positioned opposite the interior surface of the fairing, afirst side, and a second side, wherein some of the band portions have atoothed portion extending outward from the interior side, the toothedportion having a curved outer surface and a substantially flat surfacepositioned along the first side, and wherein the band portions withtoothed portions are positioned adjacent one another; and a slit betweeneach band portion allowing the band portions to separate from oneanother as the fairing breathes outward following separation from thespacecraft; a pawl with a head on one end, the head shaped to engage thecurved outer surface of one toothed portion and the substantially flatsurface of a second toothed portion; and a bar with a first endinterconnected to an end of the pawl opposite the head of the pawl and asecond end interconnected to the interior surface of the fairing;wherein the pawl slides along the toothed portions toward the firstaxial edge or the second axial edge of the fairing as the fairingbreathes outward and the pawl locks on the toothed portions to limit theamount of inward displacement experienced by the fairing as the fairingbreathes inward.

In one embodiment, the means for altering the shape of the fairingcomprises: a damper positioned along at least a portion of the arclength of the interior surface of the fairing and proximate the apex ofthe fairing, the damper comprising: a piston; a rod interconnected tothe piston; and a housing with a valve on a first end and the rodexiting a second end of the housing; wherein as the fairing breathesoutward, the piston is pulled away from the valve and toward the secondend of the housing and the housing fills with fluid that enters throughthe valve; wherein when the fairing begins to breathe inward, the damperrestrains the motion of the piston and the fluid is substantiallytrapped in the housing. In some embodiments, the housing is acylindrical housing. In additional embodiments, the valve is a one-wayvalve.

In another embodiment, the means for altering the shape of the fairingcomprises: a housing having a first end and a second end; a rod at leastpartially positioned in the housing and having a first endinterconnected to a piston and a second end opposite the first end,wherein the piston is positioned in the housing; a valve positionedproximate the first end of the housing; a first mount positionedproximate the housing first end, wherein the first mount isinterconnected to the interior surface of the fairing and the first endof the housing; a second mount positioned proximate the rod second end,wherein the second mount is interconnected to the interior surface ofthe fairing and the second end of the rod; and wherein the piston isconfigured to move away from the housing first end and is configured tonot move toward the housing first end.

In one embodiment, an apparatus for altering the shape of a fairingfollowing separation from a spacecraft is provided comprising: a fairinghaving a curved shape with an interior surface, first axial edge, asecond axial edge, an arcuate shape with an arc length and a radius, anapex between the first axial edge and the second axial edge, and aheight; an elongate member configured to be disposed along at least aportion of the arc length of the interior surface of the fairing andproximate the apex of the fairing, wherein the elongate membercomprises: a plurality of adjacent band portions, wherein each bandportion in the plurality of adjacent band portions has a rear sidepositioned adjacent the interior surface of the fairing, an interiorside positioned opposite the interior surface of the fairing, a firstside, and a second side, wherein some of the band portions have atoothed portion extending outward from the interior side, the toothedportion having a curved outer surface and a substantially flat surfacepositioned along the first side, and wherein the band portions withtoothed portions are positioned adjacent one another; and a slit betweeneach band portion allowing the band portions to separate from oneanother as the fairing breathes outward following separation from thespacecraft; a pawl with a head on one end, the head shaped to engage thecurved outer surface of one toothed portion and the substantially flatsurface of a second toothed portion; and a bar with a first endinterconnected to an end of the pawl opposite the head of the pawl and asecond end interconnected to the interior surface of the fairing;wherein the pawl slides along the toothed portions toward the firstaxial edge or the second axial edge of the fairing as the fairingbreathes outward and the pawl locks on the toothed portions to limit theamount of inward displacement experienced by the fairing as the fairingbreathes inward.

In one embodiment, a fairing is provided comprising: an interiorsurface; an exterior surface; a first axial edge; a second axial edge;an arcuate shape with a radius; an apex between the first axial edge andthe second axial edge; and an apparatus for controlling a shape of thefairing following separation from a spacecraft, the apparatuscomprising: a housing comprising: a first end; a second end; an interiorchamber; a valve proximate the housing first end and in communicationwith the interior chamber; a piston disposed and movable within theinterior chamber; and fluid positioned between the piston and the valve;and a rod having a first end and a second end, wherein the first end ofthe rod is interconnected to the piston and the second end of the rodextends out of the housing second end; a first mount interconnected tothe fairing interior surface and the housing first end; a second mountinterconnected to the fairing interior surface and the rod second end;wherein the valve permits fluid to enter the interior chamber of thehousing such that the piston and rod can move away from the housingfirst end which allows the fairing to breathe outward following fairingseparation, and wherein the valve limits fluid from exiting the housingsuch that when the fairing recoils inward during inward breathing thevalve limits movement of the rod and, in turn, limits an inwardbreathing displacement of the fairing by increasing an inward breathingstiffness of the fairing.

For purposes of further disclosure, the following references generallyrelated to mechanisms that changes the shape or stiffness of astructure, one-way locking mechanisms, and/or mechanisms for increasingfairing jettison clearance are hereby incorporated by reference in theirentireties:

U.S. Pat. No. 8,187,006 to Rudisill et al. entitled “Flexible MagneticInterconnects” discloses a magnetic interconnect that changes shape bymovement of the magnetic structure;

U.S. Pat. No. 6,126,115 to Carrier et al. entitled “Apparatus forRetaining and Releasing a Payload” discloses a latch for a payload thatuses temperature-activated shaped memory alloy (SMA) springs;

U.S. Pat. No. 9,180,982 to Baghdasarian entitled “Preload ReleasingFastener and Release System Using Same” discloses a preload reducingfastener with an integral collar adapted to change shape via the use ofa shape memory alloy;

U.S. Pat. No. 6,920,966 to Buchele et al. entitled “Remotely ReleasableSupport Strut” discloses a support strut that uses an SMA and heat tochange the shape of the part released such that a gap is created and thepart is remotely releasable;

U.S. Pat. No. 9,303,484 to Storey et al. entitled “DissolvableSubterranean Tool Locking Mechanism” discloses a locking mechanism thatuses a SMA or a controlled electrolytic material (CEM) to change theshape of a part to release the locking mechanism;

U.S. Patent Publication No. 2015/0329224 to Sachdev et al. entitled“Payload Ejection System” discloses a payload ejection system with pinsand hinges that allow motion in one direction but not other directions;and

U.S. Pat. No. 6,781,284 to Pelrine et al. entitled “ElectroactivePolymer Transducers and Actuators” discloses electroactive polymers toconvert electric energy into mechanical energy and compliant electrodesthat conform to the shape of a polymer.

For purposes of further disclosure, the following references generallyrelated to dampers and are hereby incorporated by reference in theirentireties:

U.S. Pat. No. 7,296,818 to Krumbeck et al. entitled “Combination of Skiand Ski Binding” discloses a damper for a ski binding; and

U.S. Pat. No. 6,676,151 to Mangold et al. entitled “Ski or SnowboardBinding with Counterflex Damping of the Ski” discloses a damper for aski or snowboard binding.

The phrases “at least one”, “one or more”, and “and/or”, as used herein,are open-ended expressions that are both conjunctive and disjunctive inoperation. For example, each of the expressions “at least one of A, Band C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “oneor more of A, B, or C” and “A, B, and/or C” means A alone, B alone, Calone, A and B together, A and C together, B and C together, or A, B andC together.

Unless otherwise indicated, all numbers expressing quantities,dimensions, conditions, and so forth used in the specification andclaims are to be understood as being modified in all instances by theterm “about”.

The term “a” or “an” entity, as used herein, refers to one or more ofthat entity. As such, the terms “a” (or “an”), “one or more” and “atleast one” can be used interchangeably herein.

The use of “including,” “comprising,” or “having” and variations thereofherein is meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Accordingly, the terms “including,”“comprising,” or “having” and variations thereof can be usedinterchangeably herein.

It shall be understood that the term “means” as used herein shall begiven its broadest possible interpretation in accordance with 35 U.S.C.Section 112(f). Accordingly, a claim incorporating the term “means”shall cover all structures, materials, or acts set forth herein, and allof the equivalents thereof. Further, the structures, materials, or actsand the equivalents thereof shall include all those described in thesummary of the invention, brief description of the drawings, detaileddescription, abstract, and claims themselves.

These and other advantages will be apparent from the disclosure of theinvention(s) contained herein. The above-described embodiments,objectives, and configurations are neither complete nor exhaustive. TheSummary of the Invention is neither intended nor should it be construedas being representative of the full extent and scope of the presentinvention. Moreover, references made herein to “the present invention”or aspects thereof should be understood to mean certain embodiments ofthe present invention and should not necessarily be construed aslimiting all embodiments to a particular description. The presentinvention is set forth in various levels of detail in the Summary of theInvention as well as in the attached drawings and the DetailedDescription and no limitation as to the scope of the present inventionis intended by either the inclusion or non-inclusion of elements,components, etc. in this Summary of the Invention. Additional aspects ofthe present invention will become more readily apparent from theDetailed Description, particularly when taken together with thedrawings.

The above-described benefits, embodiments, and/or characterizations arenot necessarily complete or exhaustive, and in particular, as to thepatentable subject matter disclosed herein. Other benefits, embodiments,and/or characterizations of the present disclosure are possibleutilizing, alone or in combination, as set forth above and/or describedin the accompanying figures and/or in the description herein below.However, the Detailed Description, the drawing figures, and theexemplary claims set forth herein, taken in conjunction with thisSummary of the Invention, define the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Those of skill in the art will recognize that the following descriptionis merely illustrative of the principles of the invention, which may beapplied in various ways to provide many different alternativeembodiments. This description is made for illustrating the generalprinciples of the teachings of this invention and is not meant to limitthe inventive concepts disclosed herein.

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the general description of the invention given above andthe detailed description of the drawings given below, serve to explainthe principles of the invention.

FIG. 1 is a perspective view of prior art fairings separating from thespacecraft;

FIG. 2A is a cross-sectional view of the prior art fairings on thespacecraft before the fairing have separated (at time t0);

FIG. 2B is a cross-sectional view of the prior art fairings on thespacecraft as the fairings separate from the spacecraft (at time t1 andt2);

FIG. 3A is a front elevation view of a fairing showing possiblelocations of the mechanism for increasing jettison clearance accordingto various embodiments of the present invention;

FIG. 3B is a side elevation view of the fairing with the mechanism ofFIG. 3A;

FIG. 4A is a cross-sectional view of the fairing and an embodiment ofthe mechanism taken along line IV-IV of FIG. 3B with an enlarged view ofone section;

FIG. 4B is the enlarged view of FIG. 4A as the fairing breathes outwardand the band portions of the mechanism separate;

FIG. 5A is a front elevation view of a second embodiment of themechanism for increasing jettison clearance before the fairing has beenjettisoned from the spacecraft;

FIG. 5B is a top perspective view of the mechanism of FIG. 5A before thefairing has been jettisoned from the spacecraft;

FIG. 6A is a top perspective view of the band portion of the mechanismof FIGS. 5A-B before the fairing has been jettisoned from thespacecraft;

FIG. 6B is a top perspective view of the band portion of the mechanismof FIGS. 5A-B after the fairing has been jettisoned from the spacecraft;

FIG. 7A is a front elevation view of the mechanism of FIGS. 5A-B afterthe fairing has been jettisoned from the spacecraft;

FIG. 7B is a top perspective view of the mechanism of FIG. 7A after thefairing has been jettisoned from the spacecraft;

FIG. 8 is a cross-sectional view of a spacecraft and a fairing with anyof the embodiments of the mechanism for increasing jettison clearanceprovided herein immediately after the fairing has separated from thespacecraft (time t1) and this view is taken at the same IV-IV cutlocation of FIG. 3B;

FIG. 9 is a cross-sectional view of the spacecraft and fairing of FIG. 8and a fairing without the mechanism for increasing jettison clearance ata time shortly after FIG. 8 (i.e., at time t2);

FIG. 10 is a cross-sectional view of the spacecraft and fairings ofFIGS. 8-9 at a time shortly after FIG. 9 (i.e., at time t3);

FIG. 11 is a cross-sectional view of a fairing with a fourth embodimentof the mechanism for increasing jettison clearance and this view istaken at the same IV-IV cut location of FIG. 3B;

FIG. 12 is a cross-sectional view of a fairing with a fifth embodimentof the mechanism for increasing jettison clearance with an enlarged viewof one section;

FIG. 13 is the enlarged view of FIG. 12 as the fairing breathes outwardand the band portions separate and the ratchet or pawl locks on theteeth of the band portions;

FIG. 14 shows a sixth embodiment of the mechanism for increasingjettison clearance;

FIG. 15 is a front elevation view of a mechanism for increasing jettisonclearance positioned on the fairing;

FIG. 16 is a cross-sectional view of a fairing with a sixth embodimentof the mechanism for increasing jettison clearance shown before thefairing has been jettisoned from the spacecraft (time=t0);

FIG. 17 is a cross-sectional view of the fairing and mechanism forincreasing jettison clearance of FIG. 16 shown after the fairing hasbeen jettisoned from the spacecraft (time=t1);

FIG. 18 is a cross-sectional view of a fairing with multiple mechanismsfor increasing jettison clearance shown before the fairing has beenjettisoned from the spacecraft (time=t0); and

FIG. 19 is a cross-sectional view of the fairing and mechanisms forincreasing jettison clearance of FIG. 18 shown after the fairing hasbeen jettisoned from the spacecraft (time=t1).

The drawings are not necessarily to scale and various dimensions may bealtered. In certain instances, details that are not necessary for anunderstanding of the invention or that render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION

Although the following text sets forth a detailed description ofnumerous different embodiments, it should be understood that the legalscope of the description is defined by the words of the claims set forthat the end of this disclosure. The detailed description is to beconstrued as exemplary only and does not describe every possibleembodiment since describing every possible embodiment would beimpractical, if not impossible. Numerous alternative embodiments couldbe implemented, using either current technology or technology developedafter the filing date of this patent, which would still fall within thescope of the claims.

The orientation and directions as used herein are relative to thedrawings as illustrated. Therefore, it should be appreciated that theterms “above,” “below,” “top,” “bottom,” “horizontal,” or “vertical” areused to describe the relative location of different parts of the novelmechanism to alter the breathing stiffness and displacement and areintended to include not only a vertical or horizontal alignment.Specifically, following launch, the position of the spacecraft may nolonger remain vertical but may have other orientations. Thus, the novelmechanism may be oriented differently in flight, but the relativeposition of the novel mechanism is as described.

FIG. 3A is a front elevation view of a fairing 8 showing possiblelocations of the mechanism for increasing jettison clearance and FIG. 3Bis a side elevation view of the fairing 8 with the possible mechanismlocations. The fairing 8 has a height H (measured from the bottom edge16 to the tip) and a width W, which may also be the diameter from thefirst axial edge 24 to the second axial edge. The fairing 8 has anarcuate shape with an arc length, radius, radius of curvature, aninterior surface, and an exterior surface 36. FIGS. 3A and 3B areexterior (outboard) views of the fairing 8 and the mechanism istypically located on an interior (inboard) surface of the fairing 8.Therefore, the mechanism locations 62, 64, 66 shown in FIGS. 3A-B merelyshow possible locations of the mechanisms on the fairing 8. In someembodiments, the mechanism is placed on the central section of thejettisoned structure that experiences the greatest amount of strainduring separation. This area is generally the backbone region or apex50. It is possible that the fairing 8 would include three mechanisms inthe positions 62, 64, 66 shown or may only include one or two mechanismsin any of the locations 62, 64, 66 shown. Alternatively, the fairing 8may have more than three mechanisms. The number of mechanisms used willdepend on the stiffness of the fairing 8, the size and mass of thefairing 8, and the clearance needed between the fairing 8 and thespacecraft.

The mechanisms 70 shown in FIGS. 4A-10 are placed on the inboard surface32 of the fairing 8 and are positioned proximate the apex or backboneregion 50 of the fairing 8 at one or more of the locations 62, 64, 66shown in FIGS. 3A-B. Alternatively, as shown in FIG. 11, a portion orall of the mechanism 70 can be placed on the outboard surface 36 of thefairing 8. Note that the mechanism 70 may be called an apparatus, anelongate member, or a band herein.

FIG. 4A is a cross-sectional view of the fairing 8 and mechanism 70taken along line IV-IV of FIG. 3B with an enlarged view of one section.This is a simplified embodiment of a control mechanism 70 because ituses less components than other embodiments and specifically uses lesscomponents than the embodiment shown in FIGS. 5A-7B. The mechanism 70includes a plurality of band portions 74, such that the mechanism 70 canseparate between each band portion 74 (i.e., along the horizontal lines78 shown) to allow outward expansion of the fairing 8 during outwardflexing or breathing. The band portions 74 are interconnected to theinterior surface 32 of the fairing 8 and positioned side-by-side inalignment such that their side surfaces touch the side surfaces of theirneighboring band portions 74. The apparatus 70 is positioned in ahorizontal plane (when the fairing is oriented as shown in FIGS. 3A-3B)such that the mechanism 70 is positioned along the arc length or radiusof curvature of the fairing 8. In this embodiment, the majority of theapparatus 70 is positioned on the interior surface 32 of the fairing 8,except that fasteners may extend through the fairing 8 and have aportion positioned on the exterior surface 36 of the fairing 8. Forexample, if the fastener is a bolt, then the bolt head may be positionedon the exterior surface 36 of the fairing 8. This embodiment of themechanism 70 does not alter the static form of the fairing 8. It doesnot lock the fairing 8 in a more open position during outward breathing,as is the case with other embodiments described herein. Rather, the bandportions 70 increase the inward breathing stiffness of the fairing 8 toreduce the maximum inward breathing displacement of the jettisonedfairing 8 and, thus, reduce or eliminate the risk of spacecraft orvehicle damage during fairing 8 separation. Further, the radius ofcurvature R_(C) of the portion of fairing with the mechanism 70 canincrease as the fairing 8 separates from the spacecraft and breathesoutward, but the mechanism prevents the radius of curvature R_(C) of theportion of the fairing with the mechanism 70 from decreasing much beyondits original radius of curvature R_(C) in its static, pre-separationstate. The portion of the fairing with the mechanism 70 may deflectslightly past the original radius since the band or mechanism 70 is notinfinitely rigid itself or in its attachment to the fairing. However,displacement past the original shape will be greatly reduced andminimized compared to a fairing without the mechanism 70. The number andsize of the band portions 70 depends on the mass and stiffness of thefairing 8, the amount of separation energy imparted into the fairing,and the amount of clearance needed based on the size of the payload orspacecraft.

In alternative embodiments, the mechanism 70 is one long elongate memberwith slits 78 cut along the elongate member, where the slits 78 extendthrough the elongate member from the first edge 82 (i.e., the edge 82opposite the fairing) to a second edge 84 (i.e., the edge 84 adjacentthe fairing 8). The edges 82, 84 may be called sides or side surfacesherein. In other embodiments, the elongate member has an accordion shapeand bolts with springs extend through the accordion-shaped elongatemember and through the fairing.

FIG. 4B shows the apparatus 70 of FIG. 4A at a time when the fairing 8is breathing outwardly. Here the elongate member or band portion 74 haveseparated along the separation lines 78 forming gaps 86. The separationlines 78 and gaps 86 allow the fairing to breathe or flex outward suchthat the apparatus 70 does not hinder or restrict the outward breathingor flexing of the fairing 8.

FIG. 5A is a front elevation view of a second embodiment of one portionof a mechanism for increasing jettison clearance before the structure orfairing has been jettisoned from the vehicle or spacecraft and FIG. 5Bis a top perspective view of the portion of the mechanism. The mechanismis comprised of a plurality of band portions 74 positioned side-by-side,as shown in FIG. 4A. In this embodiment, each portion of the mechanismincludes a band portion 74. The band portion 74 has an interior surface(also called inboard surface, side, or first edge) 82, an outboardsurface (also called exterior surface, side, or second edge, not shown)84 positioned adjacent the fairing, two side surfaces 88 (also called aside herein), and upper surface 90, and a bottom surface (not shown).The band portion 74 has an aperture 92 proximate the center of the bandportion 74 and a slit (also called a slot herein) 94 extending from thesecond edge or rear surface 84 proximate the fairing to the interiorsurface or first edge 82 of the band portion 74 and extending throughthe aperture 92. In other embodiments, the slit 94 extends from theaperture 92 to the interior surface (also called the first edge or side)82 of the band portion 74. The mechanism also includes a blocking member98 (which can be a pin, spring-loaded pin, cam, or wedge) having abiasing member 102 (which can be a spring or other force-exertingmechanism), one or more washers (also called plates) 106, and a lockingmechanism or platform 110 (which can be a nut). The pin 98 has a head(also called head portion) 118, cylindrical portion (also called secondbody portion) 122 opposite the head portion 118, and an enlarged portion(also called thick cylindrical portion) 126 positioned between the head118 and the cylindrical portion 122. The enlarged portion 126 mayoptionally include a tapered surface 130 proximate to and tapering intothe cylindrical body portion 122 and proximate the band portion 74 inthe non-deployed position. At least a portion of the cylindrical portion122 has threads 134 to threadingly engage a threaded inner threadedsurface of the locking mechanism or nut 110. The nut 110 is adjustableto adjust the amount of tension on the biasing member 102 and blockingmember 98.

The band portions 74 may be longer, shorter, thicker, and/or wider thanthe band portion 74 shown in FIGS. 5A-7B. Alternatively, the mechanism70 could be one or several long bands with multiple apertures 92 andblocking members 98 in a single band rather than a plurality of bandportions 74.

At time t0, before the structure is jettisoned, the biasing member 102is in compression and the enlarged cylindrical portion 126 of the pin 98is positioned above the upper surface 90 of the band portion 74. Theaperture 92 in the band portion 74 is sized to fit the cylindrical bodyportion 122 of the pin 98, but is smaller than the enlarged portion 126of the pin 98. Thus, the enlarged cylindrical portion 126 cannot fit inthe aperture 92. The spring 102 is positioned between two plates 106 andaround the cylindrical portion 122 of the pin 98 below the band portion74. One washer 106 is positioned between the band portion 74 and thebiasing member 102. Another washer 106 is positioned between the biasingmember 102 and the locking mechanism 110. The washers 106 help to evenlydistribute the force of the spring 102 on both the nut 110 and the bandportion 74. The nut 110 is positioned around the lower portion of thecylindrical body portion 122—and specifically around the threadedportion 134 of the cylindrical body portion 122. In other embodiments,devices other than a threaded shaft 134 and ring 110 could be used. Forexample, the blocking member 98 and biasing member 102 could include acotter key, cotter pin, or other structures known to those skilled inthe art.

Each side surface 88 of the band portion 74 is positioned adjacent to aside surface 88 of another band portion 74, unless the band portion 74is the endmost band portion 74 in the plurality of band portions 74. Thenumber and size of the band portions 74 is dependent on the systemdeflections, the stiffness and mass of the fairing, and the clearanceneeded by the system. The second edge (also called a side or rearsurface) 84 of the band portion 74 is positioned proximate to theinboard surface of the fairing. In some embodiments, the second edge 84of the band portion 74 may be positioned adjacent to and touching theinboard surface of the fairing.

FIG. 6A is a top perspective view of the band portion 74 of themechanism at time t0, before the fairing has been jettisoned from thespacecraft. After the fairings separate from the spacecraft and as thefairings jettison away from the spacecraft, the fairings breathe or flexoutward. As the fairings breathe or flex outward, the band portion 74separates along the slot 94, which increases the size of both theaperture 92 and the slot 94. FIG. 6B is a top perspective view of theband portion 74 of the mechanism at time t1, after the fairing has beenjettisoned from the spacecraft and as the slit 94 separates and theaperture 92 opens.

Once the aperture 92 is at least the size of the enlarged cylindricalportion 126 of the pin 98, the enlarged cylindrical portion 126 ispulled by the biasing member 102) into the now-larger aperture 92. Thisis shown in FIGS. 7A and 7B. FIG. 7A is a front elevation view of theportion of the mechanism of FIGS. 5A-B after the fairing has beenjettisoned from the spacecraft and FIG. 7B is a top perspective view ofthe portion of the mechanism. Once the enlarged portion 126 has moved toits deployed position, the enlarged portion 126 prevents the aperture 92and slit 94 from closing and returning to their original shapes, thuschanging the fairing's static form to be in a more open position andalso increasing the inward breathing stiffness of the fairing to limitthe amount the fairing can recoil or breathe inward. Additionally, thebiasing member 102 prevents the thick cylindrical portion 126 from beingforced out of the aperture 92.

In some embodiments, the pin 98 is a screw. Alternatively, the pin 98can be a rivet, wedge, or shim. In other embodiments, the pin 98 is acustom-shaped pin 98 with a head portion 118. The pin 98 can be metal,composite material, ceramic, or any other material known in the art. Theband portion 74 can be metal, composite material, ceramic, or any othermaterial known in the art. Additionally, the aperture 92 and pin 98 mayhave a different shape, e.g., square, rectangular, oval, etc. Any typeof nut 110 and/or washer 106 can be used in various embodiments,including a one-piece nut and washer. A bushing 138 is positioned aroundthe cylindrical body portion 122 of the pin 98. The bushing 138 preventsover compressing the spring, sets the spring preload, and provides forsome nominal preload in the joint to prevent the entire pin assembly orcomponent from moving or rattling during ascent.

FIG. 8 is a simplified cross-sectional view of the spacecraft 12 andfairing 8 ₁ with an embodiment of the mechanism 70 for increasingjettison clearance immediately after the fairing 8 ₁ has separated fromthe spacecraft (time t1). This cross-sectional view is taken at the sameIV-IV cut location of FIG. 3B. The mechanism 70 shown in FIGS. 8-10 canbe any of the mechanism embodiments provided herein. For illustrativepurposes, two fairings 8 ₁ are shown in FIG. 8: one fairing with themechanism 70 for increasing jettison clearance and one fairing without amechanism. The mechanism 70 has a band portion 74 directlyinterconnected to the interior surface 32 of the fairing 8. However, atthis time (t1) only one fairing 8 ₁ can be seen because the fairings 8 ₁are positioned in the same location and are just beginning to flex orbreathe outward. The axial edges 24, 28 of the fairings 8 ₁ are adistance D1 away from the spacecraft 12. The mechanism 70 in thisembodiment may be similar to the mechanism 70 shown in FIGS. 4A-7B withband portions 74.

For FIGS. 9-10, the fairing 8A without the mechanism 70 has a firstaxial edge 24A and second axial edge 28A and the fairing 8B with themechanism 70 has a first axial edge 24B and second axial edge 28B.

FIG. 9 is a cross-sectional view of the spacecraft 12 and fairings 8A₂,8B₂ of FIG. 8 at time t2, a time shortly after FIG. 8. At this time,both fairings 8A₂, 8B₂ are flexing outward before recoiling from thatexpansion. The fairing 8A₂ without the mechanism 70 is done breathingoutward and is about to begin breathing inward and the fairing 8B₂ withthe mechanism 70 continues to breathe outward. Thus, the axial edge 28Aof the fairing 8A₂ without the mechanism 70 is a distance D2 _(A) awayfrom the spacecraft 12 and the axial edge 28B of the fairing 8B₂ withthe mechanism 70 is a distance D2 _(B) away from the spacecraft 12. Thedistance D2 _(A) is less than the distance D2 _(B).

FIG. 10 is a cross-sectional view of the spacecraft 12 and fairings 8A₃,8B₃ of FIGS. 8-9 shortly after FIG. 9 (i.e., at time t3). At this time,the fairing 8A₃ without the mechanism 70 breathes inward while thefairing 8B₃ with the mechanism 70 remains in its outward breathingposition. Accordingly, the new static position of the fairing 8B₃ withthe mechanism 70 is the position shown in FIG. 10. The axial edge 28A ofthe fairing 8A₃ without the mechanism 70 is a distance D3 _(A) away fromthe spacecraft 12 and the axial edge 28B of the fairing 8B₃ with themechanism 70 is a distance D3 _(B) away from the spacecraft 12. Thedistance D3 _(A) is much less than the distance D3 _(B). Thus, thefairing 8B₃ with the mechanism 70 breathes inward less than the fairing8A₃ without the mechanism 70 because the mechanism 70 creates nonlinearstiffness characteristics, meaning the fairing 8 is softer breathingoutward and stiffer breathing inward. Further the radius of curvatureR_(A) of the portion of fairing 8A₃ proximate the apex for the fairing8A₃ without the mechanism 70 is smaller than the radius of curvatureR_(B) of the portion of the fairing 8B₃ with the mechanism 70. Thus, themechanism of the present invention prevents the radius of curvature ofthe fairing proximate the apex from decreasing below a certain radius ofcurvature, but the mechanism of the present invention does not preventthe radius of curvature of the fairing proximate the apex fromincreasing as the fairing breathes outward. For embodiments with themechanism 70, the radius of curvature can enlarge upon outwarddeflection (outward breathing), but the radius of curvature cannotdecrease much below a predetermined radius of curvature. Thepredetermined radius of curvature is either the static, pre-separationradius of curvature or the enlarged and locked open radius of curvature.The radius of curvature may decrease slightly below the predeterminedradius of curvature because the mechanism 70 is not infinitely rigiditself or in its attachment to the fairing.

FIG. 11 is a cross-sectional view of the fairing 8 with a fourthembodiment of the mechanism 70 for increasing jettison clearance andthis view is taken at the same IV-IV cut location of FIG. 3B. Thisembodiment of the novel mechanism uses a spring-tensioned webbing orstrap 160 on the outboard surface 36 of the structure (e.g., fairing 8)and each end of the strap 160 is in tension with a torsion spring housedin an inertia reel 164. The inertia reels 164 are positioned on theinboard surface 32 of the fairing 8. As the fairing 8 initially flexesor breathes outward after jettison, the inertia reels 164 move closertogether and the ends of the strap 160 are retracted into the inertialreels 164. As the fairing 8 breathes inward, the inertial reels 164 lockthe webbing or strap 160 in a new, shorter length which prevents inwardbreathing of the fairing 8. This changes both the static form of thejettisoned fairing 8 and the inward breathing stiffness of the fairing8.

In alternative embodiments of the mechanism 70 shown in FIG. 11, thefairing 8 could include two mechanisms 70 positioned at the same heighton the fairing and separated a distance from each other. One mechanism70 could be positioned proximate the first axial edge 24 and the othermechanism 70 could be positioned proximate the second axial edge 28 suchthat there is no mechanism on the spine of the fairing 8. Further, eachmechanism 70 could include an inertia reel 164 on either end of thestrap 160. Alternatively, each mechanism 70 may only have one inertialreel 164 on the end of the strap 160 proximate the spine 50 of thefairing 8.

A fifth embodiment of the novel mechanism 70 is shown in FIG. 12. Thisembodiment includes a band with band portions 74 positioned on theinboard surface 32 of the fairing 8 proximate the apex 50 of the fairing8 at one or more of the locations shown in FIGS. 3A-B. Some bandportions 74 have teeth 170 extending inwardly and away from the fairing8. In the embodiment shown, the band portions 74 proximate the edges ofthe band have teeth 170. The mechanism 70 also includes a pawl 174. Therear end of the pawl 174 is interconnected to one end of a link (alsocalled a linking member herein) 178 at an interconnection point 182. Theother end 186 of the link 178 is interconnected to the interior surface32 of the fairing 8. The pawl 174 has a head 190 opposite its rear end,where the head 190 is adapted to engage with the teeth 170 of the bandportion 74. Thus, the band portion 74 with teeth 170 acts like a ratchetwhen engaging the pawl 174. In this embodiment, as the fairing 8breathes outward during jettison, the head 190 of the pawl 174 slidespast the teeth 170. As the fairing 8 starts to breathe inward, the pawl174 catches on the teeth 170 and locks to lock the fairing 8 in a moreopen position and prevent or limit the fairing's inward displacementduring inward breathing. Thus, this embodiment changes both the staticform of the jettisoned fairing 8 and the inward breathing stiffness ofthe fairing 8.

FIG. 13 shows the enlarged portion of FIG. 12 but after the fairing 8has separated from the launch vehicle or spacecraft. Additionally, thefairing has breathed outward and the pawl 174 has moved along the teeth170 toward the end of the teeth 170. When the fairing 8 is donebreathing outward and begins to breathe inward, the pawl 174 is lockedin place in a different position than it was originally in, which, incombination with the link 178, locks the fairing 8 in a more openposition. Additionally, the mechanism 70 would also include springs orother biasing members 194 to bias the pawl 174 toward the teeth 170(and, thus, toward the fairing 8) and to prevent the pawl 174 frommoving inboard radially or moving away from the teeth 170 in anydirection. The springs or biasing members 194 may be positioned in otherlocations than that shown in FIG. 13. For example, the springs orbiasing members 194 may be positioned above or below the mechanism 70.

An alternative embodiment of the mechanism 200 includes a damper with ahydraulic or pneumatic cylinder. FIGS. 14-19 show the mechanism being adamper 200.

FIG. 14 shows a damper 200, which can be used as the mechanism forincreasing jettison clearance. The components within the damper housingare shown for clarity and discussion purposes. Typically, the componentswithin the damper housing would not be visible. The damper 200 has apiston 204 and a rod 208 is interconnected to the piston 204 on a firstend 212, where the second end 216 of the rod 208 is interconnected tothe interior surface of the fairing via a mount 220 and a fasteningdevice 224. The fastening device may be a bolt, screw, clevis, or anyother known fastening device. The damper 200 has a housing 228 with avalve 232 on a first end 236 and the rod 208 interconnected to thepiston 204 exits the housing 228 on the housing's second end 240opposite the first end 236. In one embodiment, the valve 232 is aone-way valve. In some embodiments, the housing 228 has a cylindricalshape. In the damper's 200 static state before fairing separation (FIGS.14, 16, and 18), the piston 204 is mostly in the housing 228 and ispositioned proximate the housing first end 236 with the valve 232. Asthe fairing breathes outward, the piston 204 is pulled away from thevalve 232 and toward the second end 240 of the housing 228. The housing228 fills with fluid 244 that enters through the valve 232 as the piston204 is pulled away from the valve 232 and toward the second end 240 ofthe housing 228. When the fairing begins to breathe inward, the damper200 restricts motion of the piston 204 in an inward direction, whichrestrains the fairing motion, because the fluid now in the damper cannotexit through the valve 232 or can only exit the valve 232 very slowly.Thus, the fairing is restrained in a more open position by the damper200.

FIG. 15 is a front elevation view of a fairing 8 showing some of thepossible locations of the mechanism for increasing jettison clearance200. FIG. 15 is an interior view (looking outboard) of the fairing 8because the mechanism 200 is typically located on an interior (inboard)surface of the fairing 8. Therefore, the mechanism locations shown inFIG. 15 merely show possible locations of the mechanisms on the fairing8. In some embodiments, the mechanism 200 is placed on the centralsection of the jettisoned structure that experiences the greatest amountof strain during separation. This area is generally the backbone regionor apex 50.

The fairing 8 can include any number of mechanisms 200. If the fairing 8only includes one mechanism 200 in a specific horizontal plane, then themechanism 200 can be centered on the backbone region 50 of the fairing 8as shown in FIG. 15. If the fairing 8 includes two mechanisms 200 in aspecific horizontal plane, then the mechanisms 200 may be interconnectedto the fairing 8 such that one end of each mechanism 200 is positionedon the backbone region 50, as shown in FIG. 15. The fairing 8 couldinclude all three mechanisms 200 as shown in FIG. 15, or could includemore or fewer mechanisms in various locations and orientations. Thenumber of mechanisms 200 used will depend on the stiffness of thefairing 8, the size and mass of the fairing 8, and the clearance neededbetween the fairing 8 and the spacecraft. Thus, in some embodiments,more than one damper 200 can be used. The dampers 200 may be positionedin line with one another (i.e., in the same plane) or the dampers 200may be positioned above and below one another. The dampers 200 may alsocross over one another depending on the number of dampers 200 desired.

FIG. 16 is a cross-sectional view of a fairing 8 with one damper 200shown before the fairing 8 has been jettisoned from the spacecraft(i.e., at time=t0). The damper 200 is interconnected to the interiorsurface of the fairing 8. The damper 200 may be interconnected to thefairing 8 via fastening means such as bolts, screws, devises, orspherical bearings. For example, the damper 200 could bolt onto theinterior surface of the fairing 8 and be attached with some sort ofspherical bearing or clevis attachment, such that the fairing 8 canfreely breathe outward. Here, at time t0, the damper 200 is in itsstatic state. Also at this time, the piston is positioned proximate thehousing first end 236 and proximate the valve.

FIG. 17 is a cross-sectional view of the fairing 8 and damper 200 ofFIG. 16 shown after the fairing has been jettisoned from the spacecraft(i.e., at time=t1). At this point in time the fairing 8 is breathingoutward. The damper 200 is set such that it is very underdamped, or notdamped at all, for movement in the expansion or extending direction suchthat the damper 200 does not inhibit the fairing 8 from breathingoutward. Thus, the piston can freely move away from the housing firstend 236 and toward the housing second end 240. As the piston movestoward the housing second end 240, the rod 208 moves out of the housing228 such that more of the rod 208 is out of the housing 228 than at timet0.

The damper 200 limits the amount the fairing 8 can breathe inwardbecause it is very overdamped in the compression direction, meaning thedamper 200 prevents or slows the piston from moving back toward thehousing first end 236 and, thus, prevents the rod 208 from moving backinto the housing 228. Therefore, the rod 208 remains extended, whichprevents or limits the portion of the fairing 8 interconnected to thedamper 200 from breathing inward and limits the amount the fairing canbreathe inward overall.

FIG. 18 is a cross-sectional view of a fairing 8 with two dampers 200A,200B shown before the fairing 8 has been jettisoned from the spacecraft(i.e., at time=t0). The dampers 200A, 200B are interconnected to theinterior surface of the fairing 8. The dampers 200A, 200B may beinterconnected to the fairing 8 via fastening means such as bolts,screws, devises, or spherical bearings. For example, the dampers 200A,200B could bolt onto the interior surface of the fairing 8 and beattached with some sort of spherical bearing or clevis attachment, suchthat the fairing 8 can freely breathe outward. Here, at time t0, thedampers 200A, 200B are in their static state. Also at this time, thepiston of each damper 200A, 200B is positioned proximate the housingfirst end 236 and proximate the valve. The dampers 200A, 200B arepositioned such that the housings 228 are positioned proximate thebackbone region 50 of the fairing 8 and the rods 208 are positioned awayfrom the backbone region 50. However, the dampers 200A, 200B could bepositioned in the opposite direction with their rods 208 interconnectedto the backbone region 50 of the fairing 8.

FIG. 19 is a cross-sectional view of the fairing 8 and dampers 200A,200B of FIG. 18 shown after the fairing 8 has been jettisoned from thespacecraft (time=t1). At this point in time the fairing 8 is breathingoutward. Like the damper 200 of FIGS. 16-17, the dampers 200A, 200B areset such that they are very underdamped, or not damped at all, formovement in the expansion direction. Therefore, the dampers 200A, 200Bdo not inhibit the fairing 8 from breathing outward. At time t1, more ofthe rod 208 is positioned out of the housing 228 than in FIG. 18. Alsolike the damper 200 of FIGS. 16-17, the dampers 200A, 200B limit theamount the fairing 8 can breathe inward because they are very overdampedin the compression direction, meaning the dampers 200A, 200B prevent thepistons from moving back toward the housing first ends 236 and, thus,prevent the rods 208 from moving back into the housings 228. Therefore,the rods 208 remains extended, which prevents the portion of the fairing8 interconnected to the dampers 200A, 200B from breathing inward andlimits the amount the fairing can breathe inward overall.

Mechanisms for increasing jettison clearance according to embodiments ofthe present invention can be manufactured of various materials. Forexample, in one embodiment, the mechanism is mostly metal. In anotherembodiment, the mechanism is comprised of metal components, ceramiccomponents, and/or composite material components.

Embodiments of the present invention can be manufactured using additivemanufacturing (i.e., 3D printing) technology, typical machining, custommolded, or purchased as standard parts.

Additionally, various features/components of one embodiment may becombined with features/components of another embodiment. For example,features/components of one figure can be combined withfeatures/components of another figure or features/components of multiplefigures. To avoid repetition, every different combination of featureshas not been described herein, but the different combinations are withinthe scope of this disclosure. Additionally, if details (includingangles, dimensions, etc.) about a feature or component are describedwith one embodiment or one figure, then those details can apply tosimilar features of components in other embodiments or other figures.

While various embodiments of the present invention have been describedin detail, it is apparent that modifications and alterations of thoseembodiments will occur to those skilled in the art. However, it is to beexpressly understood that such modifications and alterations are withinthe scope and spirit of the present invention, as set forth in thefollowing claims. Further, the invention(s) described herein is capableof other embodiments and of being practiced or of being carried out invarious ways. It is to be understood that the phraseology andterminology used herein is for the purpose of description and should notbe regarded as limiting.

What is claimed is:
 1. A fairing comprising: first axial edge; a secondaxial edge; an arcuate shape with a radius and an arc length from thefirst axial edge to the second axial edge; a longitudinal centerlinebetween the first axial edge and the second axial edge; a height; and ameans for altering the shape of the fairing following separation from aspacecraft, wherein the means for altering the shape of the fairing hasa first position at a time prior to separation from the spacecraft and asecond position at a time after separation from the spacecraft, whereinwhen the means for altering the shape of the fairing is in the firstposition a portion of the fairing proximate the longitudinal centerlineand extending a length on either side of the longitudinal centerline hasa first radius of curvature and when the means for altering the shape ofthe fairing is in the second position the portion of the fairingproximate the longitudinal centerline has a second radius of curvaturethat is larger than the first radius of curvature, and wherein the meansfor altering the shape of the fairing limits the portion of the fairingproximate the longitudinal centerline from returning to the firstposition.
 2. The fairing of claim 1, wherein the means for altering theshape of the fairing comprises: an elongate member disposed along atleast a portion of the arc length of the interior surface of thefairing, the elongate member having a first end and a second end,wherein the first and second ends are disposed on opposite sides of thelongitudinal centerline of the fairing, the first end comprising a firsttoothed ratchet and the second end comprising a second toothed ratchet,wherein the first and second toothed ratchets each have a plurality ofteeth extending inwardly, the elongate member comprising a plurality ofadjacent band portions; a first pawl having a first end and a secondend, a head disposed on the first end and shaped to engage the firsttoothed ratchet, the second end secured to the fairing; and a secondpawl having a first end and a second end, a head disposed on the firstend and shaped to engage the second toothed ratchet, the second endsecured to the fairing.
 3. The fairing of claim 2, wherein the firstpawl is configured to move along the plurality of teeth of the firsttoothed ratchet toward the first axial edge of the fairing and thesecond pawl is configured to move along the plurality of teeth of thesecond toothed ratchet toward the second axial edge of the fairing asthe fairing expands outward and the first pawl locks on to a toothedportion in the plurality of teeth of the first toothed ratchet and thesecond pawl locks on to a toothed portion in the plurality of teeth ofthe second toothed ratchet to limit the amount of inward displacementexperienced by the fairing as the fairing contracts inward.
 4. Thefairing of claim 2, wherein the elongate member further comprises a slitbetween each band portion allowing these band portions to separate fromone another as the fairing expands outward following separation from thespacecraft.
 5. The fairing of claim 2, wherein the teeth in theplurality of teeth of the first toothed ratchet and the teeth in theplurality of teeth of the second toothed ratchet have a first sideopposite a second side and a curved or angled surface extending betweenthe first and second sides, wherein the first and second sides aresubstantially parallel to one another and the first side is longer thanthe second side.
 6. The fairing of claim 1, wherein the means foraltering the shape of the fairing comprises: a housing having a firstend, a second end, and an opening on the second end, the first endinterconnected to an interior surface of the fairing; a pistonpositioned in the housing, the piston configured to move linearly withinthe housing; a rod having a first end interconnected to the piston and asecond end opposite the first end, the rod first end positioned in thehousing, the rod second end positioned outside of the housing andinterconnected to the interior surface of the fairing; and a valvepositioned proximate the first end of the housing and fluid positionedbetween the piston and the valve, wherein the valve is configured topermit the piston to move away from the housing first end and isconfigured to restrict the piston from moving toward the housing firstend.
 7. The fairing of claim 6, further comprising: a first mountinterconnected to the housing first end, wherein the first mount isinterconnected to the interior surface of the fairing; and a secondmount interconnected to the rod second end and interconnected to theinterior surface of the fairing.
 8. The fairing of claim 6, wherein thevalve permits fluid to enter the housing such that the piston and rodmove away from the housing first end, which allows the fairing to expandoutward following separation from the spacecraft, and wherein the valvelimits fluid from exiting the housing such that when the fairing recoilsinward the rod and housing limit an inward contraction of the fairing bycreating a resistance to an inward contraction stiffness of the fairing.9. The fairing of claim 1, wherein the means for altering the shape ofthe fairing comprises: a spring-tensioned webbing having a first end anda second end, the spring-tensioned webbing positioned on an exteriorsurface of the fairing and extending along a portion of the fairing arclength, wherein the first end of the webbing is positioned on a firstside of the longitudinal centerline of the fairing and the second end ofthe webbing is positioned on the opposite side of the longitudinalcenterline from the first end; and a first inertia reel having a firsttorsion spring associated with the first inertia reel, the first end ofthe spring-tensioned webbing is in tension with the first torsionspring, wherein when the means for altering the shape of the fairing isin the first position at the time prior to fairing separation from thespacecraft the spring-tensioned webbing has a first webbing length asmeasured from the first inertia reel to the second end of thespring-tensioned webbing, and when the means for altering the shape ofthe fairing is in the second position at the time after fairingseparation from the spacecraft the spring-tensioned webbing has a secondwebbing length as measured from the first inertia reel to the second endof the spring-tensioned webbing, and wherein the second webbing lengthis shorter than the first webbing length.
 10. The fairing of claim 9,wherein the means for altering the shape of the fairing furthercomprises: a second inertia reel having a second torsion springassociated with the second inertia reel, the second end of thespring-tensioned webbing is in tension with the second torsion spring,wherein the second inertia reel is positioned on the interior surface ofthe fairing, wherein the first webbing length is measured from the firstinertia reel to the second inertia reel and the second webbing length ismeasured from the first inertia reel to the second inertia reel.
 11. Amechanism for increasing jettison clearance, comprising: an elongatemember disposed along a portion of an arc length of an interior surfaceof a jettisoned structure and proximate an apex of the jettisonedstructure, the elongate member comprising: a plurality of adjacent bandportions, wherein each band portion in the plurality of adjacent bandportions has a toothed portion extending inward from the interiorsurface of the jettisoned structure, wherein the toothed portions form aratchet; and a slit between each band portion allowing the band portionsto separate from one another as the jettisoned structure expands outwardfollowing jettison; and a first pawl with a head on a first end and asecond end opposite the first end, the head shaped to engage a firstgroove formed between the toothed portion of a first band portion andthe toothed portion of a second band portion, wherein when the fairingis in a first state the first pawl is located in the first groove, andwhen the fairing is in a second state the first pawl is located in asecond groove formed between the toothed portion of a third band portionand the toothed portion of a fourth band portion, and wherein the secondgroove is closer to a first axial edge of the jettisoned structure thanthe first groove.
 12. The mechanism for increasing jettison clearance ofclaim 11, further comprising a bar with a bar first end interconnectedto the second end of the first pawl and a bar second end interconnectedto the interior surface of the fairing, wherein a length of the bar doesnot change as the jettisoned structure expands outward and contractsinward.
 13. The mechanism for increasing jettison clearance of claim 11,wherein the toothed portions have a curved or angled surface positionedbetween a first substantially flat surface positioned opposite a secondsubstantially flat surface, wherein the first substantially flat surfaceis longer than the second substantially flat surface.
 14. The mechanismfor increasing jettison clearance of claim 11, further comprising: afirst bar with a first end interconnected to the second end of the firstpawl and a second end interconnected to a first portion the interiorsurface of the fairing; a second pawl with a head on a first end and asecond end opposite the first end, the head shaped to engage a thirdgroove formed between the toothed portion of a fifth band portion andthe toothed portion of a sixth band portion; and a second bar with afirst end interconnected to the second end of the second pawl and asecond end interconnected to a second portion the interior surface ofthe fairing, wherein when the fairing is in the first state the secondpawl is located in the third groove, and when the fairing is in thesecond state the second pawl is located in a fourth groove formedbetween the toothed portion of a seventh band portion and the toothedportion of a eighth band portion, and wherein the fourth groove iscloser to a second axial edge of the jettisoned structure than the thirdchannel.
 15. The mechanism for increasing jettison clearance of claim14, wherein a first length of the first bar does not change as thejettisoned structure expands outward and contracts inward and a secondlength of the second bar does not change as the jettisoned structureexpands outward and contracts inward.
 16. A mechanism for increasingjettison clearance, comprising: a housing comprising: a first endinterconnected to an interior surface of a jettisoned structure; asecond end; a valve proximate the housing first end; a piston; and fluidpositioned between the piston and the valve; and a rod having a firstend and a second end, wherein the first end of the rod is interconnectedto the piston and the second end of the rod extends out of the housingsecond end and is interconnected to the interior surface of thejettisoned structure, wherein the valve permits fluid to enter thehousing such that the piston and rod move away from the housing firstend, which allows the jettisoned structure to expand outward followingjettison, and wherein the valve limits fluid from exiting the housingsuch that when the jettisoned structure recoils inward the rod andhousing limit an inward displacement of the jettisoned structure bycreating a resistance to recoil of the jettisoned structure.
 17. Themechanism for increasing jettison clearance of claim 16, furthercomprising a length measured from the first end of the housing to thesecond end of the rod, wherein the valve is configured to permit thepiston to move away from the housing first end and is configured toresist movement of the piston toward the housing first end such that thelength will remain the same increase.
 18. A mechanism for increasingjettison clearance, comprising: a webbing having a first end and asecond end interconnected to a jettisoned structure, the webbingpositioned on an exterior surface of the jettisoned structure andextending along a portion of the jettisoned structure such that aportion of the webbing is positioned on a backbone of the jettisonedstructure; a first inertia reel having a first torsion spring associatedwith the first inertia reel, the first end of the webbing is in tensionwith the first torsion spring, wherein the first inertia reel ispositioned on an interior surface of the jettisoned structure; a firstposition at a time prior to jettison; and a second position at a timeafter jettison, wherein when the mechanism for increasing jettisonclearance is in the first position the webbing has a first webbinglength as measured from the first inertia reel to the webbing secondend, wherein when the mechanism for increasing jettison clearance is inthe second position the webbing has a second webbing length as measuredfrom the first inertia reel to the webbing second end, and wherein thesecond webbing length is shorter than the first webbing length.
 19. Themechanism for increasing jettison clearance of claim 18, furthercomprising a second inertia reel having a second torsion springassociated with the second inertia reel, the second end of the webbingis in tension with the second torsion spring, wherein the second inertiareel is positioned on the interior surface of the jettisoned structure.